Insulin binding to human erythrocytes has been evaluated in a number of different conditions that affect carbohydrate metabolism, in adults and in children. Such conditions include anorexia nervosa, lipoatrophic diabetes, hypercortisolism, glycogen storage diseases, nesidioblastosis, diabetes mellitus, insulin resistance and acanthosis nigricans (Type A and B), insulinomas, obesity. Insulin binding to monocytes was also evaluated in adults in many of the above listed diseases.